A liquid type chemical heating, volatilizing apparatus has been known that is serviceable for a long time period, e.g., 12 hours or more.
Such a liquid type chemical heating, volatilizing apparatus makes use of a liquid chemical formed by dissolving a chemical in a solvent. In the apparatus, the liquid chemical is drawn up and partially heated (a system of this type hereinafter referred to as “a partially heated system”) to cause the chemical to volatilize.
Such a partially heated system has an advantage in the ability to keep the liquid chemical constantly refreshed and hence in the easiness to preserve the chemical's efficacy stably for long.
However, the need for the section where the liquid chemical with the chemical dissolved in the solvent is retained, i.e., a chemical storage container and the section where it is heated to be held separately each from other and the need for the liquid chemical drawn up to be lower in viscosity, hence for the liquid chemical in its storage container to be thinner in chemical's concentration and thus to be larger in volume are entailed, which give the apparatus a disadvantage that it must on the whole be relatively large in size.
The partially heated system further requires the chemical in the liquid chemical to be held at a fixed density in order to cause the chemical to volatilize stably. Otherwise, not only is the chemical discharged but also the solvent must be emitted into the atmosphere, possibly affecting the environment adversely.
As an alternative apparatus, a whole heated system has also been known in which a chemical containing or carrier body is heated on its entirety by a heater element to cause the chemical contained therein to volatilize.
In such a whole heated system, the chemical retaining section and its heating section are naturally united together, making it possible to make up the apparatus in a compact design.
This also makes it unnecessary to hold the chemical in a constant density as required in the partially heated system. With no additional emission of such as solvent, therefore, the whole heated system is by nature pro-environmental.
The known, whole heated, chemical volatilizing apparatus using the conventional, whole heated, chemical containing body, however, makes it extremely difficult to cause the chemical to volatilize stably for a long time period.
That is, the conventional whole heated, chemical containing body used in the whole heated, chemical volatilizing apparatus so far made has had a thickness of around 2 mm, which has so limited its chemical content that it cannot keep the chemical volatilizing for long.
Making the plane geometry of the chemical containing body larger in size may make its chemical content larger in amount. But, the household use of the chemical heating, volatilizing apparatus imposes a limitation on its plane geometrical size from a requirement for its portability and from a limitation such as of the space of its set place. Also, requirements based on power consumption by the heater element impose a limitation on its plane geometrical size and in turn that of the chemical containing body.
A chemical heating, volatilizing apparatus has also been known that has an indicator set on its chemical heating, volatilizing vessel, in which the indicator displays a start and an end point of the chemical, thereby conveying to the user the depletion of the effective ingredient in the chemical.
Such an indicator makes use of a material that when heated changes its color, e.g., a thermally color changing lamination as disclosed in JP55-152059 A. In the indicator proposed in this patent literature, the thermally color changing lamination is heated by heat emitted from the heater element while the chemical is heated to volatilize thereby to cause the lamination to change its appearance from a colorless to a colored appearance, and the completion of the color change is made coincident with the depletion of the effective ingredient of the chemical, i.e., with its end point.
Indicators have also been proposed in which color change is used to display the characters “END”, or a sheet in its entirety discolors to display the end point.
However, merely presenting a change from a colorless to a colored appearance or from one color to another color makes it obscure and hard to discriminate the end point, and thus makes it difficult for the user to notice the depletion of the effective ingredient of the chemical.
Accordingly, it is an object of the present invention to provide a whole heated, chemical containing or carrier body that can volatilize a chemical stably for an extended time period.
It is also an object of the present invention to provide a chemical containing or carrier body retaining receptacle whereby vapor of the chemical can pass smoothly between an inner surface of the receptacle and the chemical containing body and can diffuse through a vent hole into its outside.
It is also an object of the present invention to provide a chemical heating, volatilizing apparatus that can be made in a compact design.
It is also an object of the present invention to provide an indicator for a heat volatilizing chemical that enables the user to clearly recognize the depletion of the effective ingredient of the chemical.